News Release

ISMP Adds Seven Name Pairs to List of Drug Names with Tall Man (Mixed Case) Letters

Recently the Institute for Safe Medication Practices (ISMP) updated its list of medication name pairs with recommended tall man letters, which are intended to differentiate look-alike drug names using uppercase and bolded text. Changes included adding new pairs based on analysis of reported events and input from an ISMP survey of healthcare practitioners. Survey participants confirmed that the use of tall man lettering is an important risk-reduction strategy.

Since 2008, ISMP has maintained a list of drug names with recommended uppercase and bolded letters, mostly pairs involving two generic drugs. The majority of respondents to ISMP’s recent survey (95%) agreed that the use of tall man letters by the pharmaceutical industry on product and carton labels helps prevent errors. In addition, 87% of respondents were able to recall one or more instances when tall man lettering had prevented them personally from prescribing, transcribing, dispensing, or administering the wrong medication.

“Tall man lettering is clearly an effective way to help prevent errors, and can be done at low or no cost,” says ISMP President Rita K. Jew, PharmD, MBA, BCPPS, FASHP. “ISMP strongly encourages FDA, pharmaceutical industry, outsourcers and compounders, hospitals, and other practice sites to continue to use tall man lettering while further studies examine the best way to differentiate look-alike names when selecting drug containers from a shelf or from listings on a computer or device screen.”

The new name pairs that have been added are:

  • cycloPHOSphamide (can be confused with cycloSPORINE and cycloSERINE, already on FDA list)
  • droPERidol and droNABinol
  • dexAMETHasone and dexmedeTOMIDine
  • pyRIDostigmine and PHYSostigmine
  • ALfentanil (can be confused with SUFentanil and fentaNYL, already on the ISMP list)
  • BUPivacaine and ROPivacaine
  • oxyBUTYnin (can be confused with oxyCODONE, OxyCONTIN, and oxyMORphone, already on the ISMP list)


While numerous studies have demonstrated the ability of mixed case lettering to reduce the risk of errors, gaps still exist in our full understanding of the role that it plays in the clinical setting. ISMP is participating in a four-year Northwestern University research project to assess the comparative effectiveness of various methods of drug name text enhancements and the ability of tall man lettering to reduce errors during selection.

For a copy of an ISMP Medication Safety Alert!® Acute Care newsletter article summarizing survey results, changes to the list, and names considered, visit: ISMP Updates Its List of Drug Names with Tall Man (Mixed Case) Letters Based on Survey Results | Institute For Safe Medication Practices

For a copy of the updated ISMP list of look-alike drug names with recommended tall man (mixed case) letters, visit: Look-Alike Drug Names with Recommended Tall Man (Mixed Case) Letters | Institute For Safe Medication Practices (

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